CVE-2026-56316

Cap-go before 12.128.2 contains an information disclosure vulnerability in the OPTIONS /build/upload/:jobId/* endpoint that allows unauthenticated attackers to enumerate valid builder job IDs through observable response discrepancies. Attackers can probe the endpoint without authentication to distinguish valid job IDs from invalid ones and generate sustained unauthenticated traffic for resource consumption.

CVSS 4.0

6.9CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

CVSS 3.1

5.3CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

EPSS

0.4% chance of exploitation in the next 30 days; higher than 34% of CVEs (scores of 2026-10-25)

CWE

CWE-203

Published

2026-06-21

Modified

2026-10-25

Record from

the NVD, synced 2026-10-25

References

• https://github.com/Cap-go/capgo/security/advisories/GHSA-9c2x-7h5x-37gm
• https://www.vulncheck.com/advisories/cap-go-job-existence-oracle-via-unauthenticated-options-build-upload-jobid
• https://github.com/Cap-go/capgo/security/advisories/GHSA-9c2x-7h5x-37gm

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